1. Field of the Invention
The present invention relates to a method and apparatus for shaping the space at the center of rolls of toilet paper.
2. Description of the Prior Art
There are toilet rolls that use a paper cylinder to form the space at the center of the roll, and there are toilet rolls that do not use such a paper cylinder, using instead the inner surface of the roll to form the center space. Each type of toilet roll is formed by winding a prescribed length of a wide strip of toilet paper to form a log roll, which is cut into sections of prescribed width to simultaneously form multiple toilet rolls. In the cutting process, the pressure of the cutter blade has the effect of deforming the roundness of the center space, whether a paper cylinder is being used or not.
This deformation has an adverse affect on the appearance of the toilet roll and degrades its commercial value, and in addition makes it difficult to insert a shaft into the center space to mount the toilet roll on a holder. When there is a large degree of deformation, the practice has been to insert a thin rod into the center space to manually restore it to a more or less round shape, but having to do this to the rolls one at a time is very time-consuming and inefficient.
Mechanizing the insertion of the rod is accompanied by the risk that in the insertion process, friction between the rod and the wall of the center space will cause tearing of the wall layers. Moreover, with some types of deformation it is difficult to ensure the proper shape of the roll, as the roll may soon revert to the deformed shape after the rod is simply inserted and withdrawn.
An object of this invention is to provide a method and apparatus that can reliably restore the round shape of the center space of toilet rolls without damaging the wall of the center space.
Another object of the invention is provide a method and apparatus for shaping the center space of toilet rolls automatically and with good efficiency.